Despite considerable methodological and empirical developments in the economic assessment of adult substance abuse programs, economic evaluation techniques have not yet been systematically adopted in studies of adolescent addiction treatment. The economic evaluation of adolescent addiction treatment is considerably more complex than that of adult treatment because of the diversity of juvenile delivery systems, the absence of standardized instrumentation or modules, the integral participation of parents/guardians and other family members, and the unique social and economic outcomes. In response to the pressing need to improve and increase economic evaluations of adolescent addiction interventions, the present project will address the following three aims: 1. Implement experience gained from conducting numerous economic evaluations of adult substance abuse interventions to develop standardized and rigorous methods for estimating the costs and economic benefits of adolescent substance abuse interventions; 2. Develop economic evaluation modules for adolescent substance abuse interventions that future studies could easily add to their design and instrumentation in order to collect the data and measures necessary to complete a cost-effectiveness analysis (CEA) or benefit-cost analysis (BCA); Simultaneously assess current economic evaluation methods and define measures for the proposed economic evaluation modules by adding an economic evaluation component to several NIDA- or CSAT-funded adolescent intervention projects in California, Colorado, Florida, Illinois, New Mexico, and South Carolina. The proposed study will complement and extend a nearly completed research grant with NIDA focused on developing and testing economic evaluation methods for adult drug abuse interventions, including the application of clinical and financial instruments in economic evaluation (1 R01 DA11506). To provide an empirical laboratory for testing these methods with adolescents, the investigative team has assembled an impressive group of NIDA and CSAT grantees that have agreed to provide access to outcome and other data. The proposed study will (1) build upon the foundation of a productive NIDA-funded research program to develop economic analysis methods and measures specifically for the evaluation of adolescent addiction interventions; (2) test the feasibility and integrity of these economic analysis methods through collaborations with NIDA/CSAT-funded scientists and "real-world" applications based in six different states; and (3) disseminate the techniques, guidelines, data collection modules, and empirical findings to the widest possible audience through peer-reviewed research papers, professional conference presentations, policy workshops, clinical workshops, website postings, and informal distribution channels.